'All else equal' ;-) I like that...
Higher symbol rate => higher bandwidth amplitude(above noise)
product. I've been told by a guy who attends the standards
committee meetings for 'cellular telephony' that the US military
is running voice at 2kbps. The voice is deconstructed and
a representative description sent. This is used to reconstruct
the 'voice' at the other end. Your home telephone is digitized
as 8bit x 8ksps and transmitted as either 7 or 8 bit x 8ksps.
(64kbps or 56kbps)
CDMA specs make for some interesting reading. Also look at what
Flarion is doing with their digital radio which may be better and
doesn't fall under Qualcomm patents! Little google work will find
it all on line...
-bob
ah7i/4
Gary Hoffman wrote:
> Well... I hafta put my two cents into this one...
>
> Digital modes CAN be very efficient and very effective in their
> use of spectrum. Consider PSK31 for instance, where you can have
> several "conversations" within the "normal" passband of one SSB signal.
>
> On the other end of the spectrum could be digital voice... Anyway...higher
> symbol rates make for wider bandwidth signals, all else being equal.
>
> On the other hand... all else Doesn't have to be equal. What I would be
> interested in would be narrow digital voice. Hope we can get there.
>
> 73 de Gary, AA2IZ
>
>
> ----- Original Message -----
> From: "Duane Grotophorst" <n9dg@yahoo.com>
> To: "john" <johnmb@nc.rr.com>; "Ken Hopper Amateur Radio N-9-V-V"
> <n9vv@wideopenwest.com>; "tentec" <tentec@contesting.com>; "Orion Discussion
> Group" <TenTec_Orion@yahoogroups.com>; "Jupiter TT538"
> <jupiter538@yahoogroups.com>
> Sent: Monday, November 25, 2002 10:13 AM
> Subject: Re: [TenTec] World's first transatlantic digi voice
>
>
>
> --- john <johnmb@nc.rr.com> wrote:
>
>>Great! More digital noise in the bands. Just what we
>>need!
>
>
> With a sentiment like what I think that comment
> represents, it is amazing that we still have any bands
> at all to operate anymore!!!
>
>
> Ponder:
>
> Circa 1955 - "Great! More Donald Duck noise in the
> bands. Just what we need!"
>
> Circa 1930 - "Great! More voice signals in the bands.
> Just what we need!"
>
> Circa 1920 - "Great! More single tone pure CW signals
> in the bands. Just what we need!"
>
>
> Whether this particular mode is truly effective or not
> for communications in the way that hams typically do
> will need to proven over time. But to unequivocally
> and offhandedly disparage it is counter to one of the
> main "basis and purpose" definitions of ham radio -
> see part 97.1(b).
>
> Duane
> N9DG
>
>
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